Microelectromechanical systems (MEMS) devices are electro-mechanical systems often incorporated into integrated circuit devices, such as integrated circuit devices fabricated using complementary metal-oxide-semiconductor (CMOS) fabrication technologies (referred to as CMOS devices). Current MEMS device fabrication methods present difficulty. For example, for MEMS sensors, thick structure layers (for example, greater than about 25 μm) are typically required to fabricate the proof mass so that inertia force is increased for improving device performance. The sensor structures for such MEMS sensors thus often have large dimensions to achieve soft spring or torsion-type (or seesaw-type structures). In another example, MEMS microphones typically require two structure layers. Conventional fabrication techniques require trench sealing/filling processes. It has been observed that the thickness of the structure layers during fabrication present difficulty when filling/sealing the trenches. Accordingly, although existing MEMS devices and methods for manufacturing MEMS devices have been generally adequate for their intended purposes, they have not been entirely satisfactory in all respects.